Solar Battery Charger For Ni-MH Batteries from article.

I have revised my previous idea & I want to use this design () since it is affordable for me.

I just have a few questions about this design.

1.I don't want to have the 12v output. Can I safely remove that or is it hardwired to the point where it can not be removed.

2.I would like to know if I could use my 5v 500mah solar panel. Because at most I will only charge 2 batteries at once which I am sure will take a while.

Thanks.

The circuit in the link has many errors that need fixing and must be completely re-designed to use your 5V solar panel.
Go to www.batteryuniversity.com to learn about the important steps in charging Ni-MH battery cells, then find a battery charger IC that does all the steps. The simple circuit you showed does not detect a full charge, instead it stops when the battery is under-charged or over-charged.